The field of the disclosure relates generally to explosive trace detection (ETD) systems and, more particularly, to systems and methods for trace detection using dual ionization sources.
Various technologies exist for detection of substances of interest, such as explosives and illicit drugs. Some trace detection technologies use spectrometric analysis of ions formed by ionization of vapors of substances of interest. Spectrometric analysis includes ion mobility spectrometry and mass spectrometry, for example, both of which are common in trace detection.
Ionization is a process by which electrically neutral atoms or molecules acquire a negative or positive charge by gaining or losing electrons, by undergoing a reaction, or by combining with an adduct that imparts a positive or negative charge. The electrically charged atoms or molecules are referred to as ions. Ionization occurs when sufficiently energetic charged particles or radiant energy travel through gases. For example, ionization occurs when an electric current is passed through a gas, if the electrons constituting the current have sufficient energy to force other electrons from the neutral gas molecules. Ionization also occurs, for example, when alpha particles and electrons from radioactive materials travel through a gas. Numerous ionization sources are used today for a variety of purposes. Radioactive ionization sources are prevalent in ETD.